3. Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities, Current [Abstract]
Accrued payroll	$ 228	$ 193
Accrued vacation	278	311
Accrued bonus	0	245
Employee benefits payable	31	0
Other	91	79
Total accrued expenses	$ 628	$ 828